According to the lawsuit, the investigation began in Connecticut in 2014 and "uncovered evidence of a broad, well-coordinated and long-running series of schemes to fix the prices" for a number of generic drugs in the U.S. The suit notes some prices increased 1,000 percent or more.

The plaintiffs say the pharmaceutical companies worked together to reduce market competition to keep prices higher and collectively agreed to raise prices for some drugs.

A delayed-release version of the antibiotic doxycycline and diabetes medicine Glyburide are the two generics mentioned by name in the suit. However, the investigation is ongoing and more lawsuits could be filed.